Bendix Commercial Vehicle Systems GEN 5 ABS - Manual (Page 47)

47
Fault Codes
ABS — Antilock Brake System.
ABS Event — Impending wheel lock situation that causes the
ABS controller to activate the modulator valve(s).
Air Gap — Distance between the Sensor and tone ring.
Anti-Compounding Valve — Prevents the application of the
service and spring brakes at the same time. Depending on
vehicle design, the anti-compounding valve may be installed in
combination with a relay valve or quick release valve.
Apply Timing — The time from the movement of the service
brake control for each brake chamber to reach 60 psi, with an
initial service reservoir pressure of 100 PSI.
ASR — Automatic Slip Regulation. Another name for traction
control.
ATC — Automatic Traction Control. An additional ABS function
in which engine torque is controlled and brakes are applied
differentially to enhance vehicle traction.
ATC Light — A light that indicates when traction control is
operating.
Channel — A controlled wheel site.
CAN — Controller Area Network. J1939 is an SAE version of
the CAN link.
Clear Codes — System to erase historical faults from the ECU,
from either the Diagnostic Button or from a hand-held diagnostic
tool (only repaired faults may be cleared).
Coefficient of Friction — The horizontal force required to move
a body (on a relatively smooth level surface) divided by the weight
of the body.
Configuration — The primary objective is to identify a “normal”
set of sensors and modulators for the Electronic Control Unit, so
that it will identify future missing sensors and modulators.
Crack Pressure — The ascending input pressure or input force
to an air valve required to initiate output pressure of flow.
Diagonal Control — ABS is configured with two diagonal circuits.
Diagonal control allows each control circuit to provide electrical
control of modulator valves on opposite sides of the vehicle.
Diagnostic Connector — Diagnostic receptacle in vehicle cab
for connection of J1587 hand-held or PC based test equipment.
The tester can initiate test sequences, and can also read system
parameters.
Diagnostic Switch — A switch used to activate blinks codes.
Diagnostic Trouble Code — A condition that interferes with the
generation or transmission of response or control signals in the
vehicle's ABS system that could lead to the functionality of the
ABS system becoming inoperable in whole or in part.
Differential Braking — Application of brake force to a spinning
wheel so that torque can be applied to wheels which are not
slipping.
ECU — Electronic Control Unit.
FMVSS-121 — Federal Motor Vehicle Safety Standard which
regulates air brake systems.
Friction Sleeve — A beryllium copper sleeve which has fingers
cut into it. It is pressed between an ABS sensor and mounting
hole to hold the sensor in place.
Indicator Lamp — An amber light which indicates the operating
status of an antilock system. When the indicator lamp is on,
ABS is disabled and the vehicle reverts to normal brake operation.
IR — Independent Regulation. A control method in which a wheel
is controlled at optimum slip, a point where retardation and
stability are maximized. The brake pressure that is best for the
wheel in question is directed individually into each brake chamber.
J1587 — The SAE heavy duty standard diagnostic data link.
J1708 — An SAE standard which defines the hardware and
software protocol for implementing 9600 baud heavy vehicle data
links. Both J1587 and J1922 are versions of J1708 data links.
J1922 — The SAE heavy vehicle data link which operates
according to J1708 protocol. It is generally used for ATC or
automatic transmission interface to an engine.
J1939 — A high speed 250,000 baud data link which is expected
to replace J1922.
MIR — Modified Independent Regulation. A method of controlling
the opposite sides of a steer axle during ABS operation so that
torque steer and stopping distance are minimized. Usually control
begins at pure select low and moves towards independent control
as the cycle progresses.
PLC — Power Line Carrier. The serial communication protocol
used to communicate with the trailer over the blue full time power
wire.
PMV — Pressure Modulator Valve. An air valve which is used to
vent or block air to the brake chambers to limit or reduce brake
torque.
QR — Quick Release. Quick release Valves allow faster release
of air from the brake chamber after a brake application. To balance
the system, quick release valves have hold off springs that
produce higher crack pressures (when the valves open).
Relay Valve — Increases the application speed of the service
brake. Installed near brakes with larger air chambers (type 24 or
30). The treadle valve activates the relay valve with an air signal.
The relay valve then connect its supply port to its delivery ports.
Equal length air hose must connect the delivery ports of the relay
valve to the brake chambers.
Release Timing — The measurement in time from initial brake
movement to reach 5 psi with 95 psi initial pressure at the brake
chambers.
Retarder Relay — A relay which is used to disable a retarder
when ABS is triggered.
Select High — A method of ABS control in which the brake torque
is released at several wheels when the last wheel begins to lock.
Select Low — The brake pressures level is the same on both
wheels of a given axle. The pressure level is based on the wheel
which is running at the lower friction coefficient.
Select Smart — The difference in pressure between the left and
right brake chamber does not exceed a certain amount. This
leads to the wheel which is running at the high friction coefficient
being braked less strongly.
Sensor Bushing — A bushing which is pressed into steer axles
to hold a wheel speed sensor and friction sleeve.
Stored Faults — A Fault that occurred.
TCS — Traction Control System, another name for ATC or ASR.
Tone Ring — A ring that is usually pressed into a wheel hub that
has a series of teeth (usually 100) and provides actuation for the
speed sensor. Note maximum run out is .008.
Glossary